2020 day 5 and 6

2020/05/part1.js

@@ -0,0 +1,39 @@
+const fs = require('fs');
+
+const data = fs.readFileSync('input.txt', 'utf-8');
+const lines = data.split('\n');
+
+let max = 0
+// who really needs semicolons anyway
+for (let i = 0; i < lines.length; i++) {
+  let line = lines[i]
+  let rowCode = line.substring(0, 7).replace(/F/g, "0").replace(/B/g, "1")
+  let colCode = line.substring(7).replace(/L/g, "0").replace(/R/g, "1")
+
+  // another excuse to flex that recursive muscle
+  function getIndexFromBSP (BSP, min, max) {
+    if (BSP.length != 1) { 
+      [min, max] = getIndexFromBSP (BSP.substring(0, BSP.length-1), min, max)
+    }
+
+    switch (BSP[BSP.length-1]) {
+      case '0':
+        max = Math.floor((min + max) / 2)
+        break
+      case '1':
+        min = Math.ceil((min + max) / 2)
+        break
+      default:
+        console.log("something went wrong")
+    }
+
+    return [min, max]
+  }
+  let row = getIndexFromBSP(rowCode, 0, 127)[0]
+  let col = getIndexFromBSP(colCode, 0, 7)[0]
+
+  let seatID = (row * 8) + col
+
+  max = seatID > max ? seatID : max
+}
+console.log(max)

2020/05/part2.js

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+const fs = require('fs');
+
+const data = fs.readFileSync('input.txt', 'utf-8');
+const lines = data.split('\n');
+
+let seats = []
+// who really needs semicolons anyway
+for (let i = 0; i < lines.length; i++) {
+  let line = lines[i]
+  let rowCode = line.substring(0, 7).replace(/F/g, "0").replace(/B/g, "1")
+  let colCode = line.substring(7).replace(/L/g, "0").replace(/R/g, "1")
+
+  // another excuse to flex that recursive muscle
+  function getIndexFromBSP (BSP, min, max) {
+    if (BSP.length != 1) { 
+      [min, max] = getIndexFromBSP (BSP.substring(0, BSP.length-1), min, max)
+    }
+
+    switch (BSP[BSP.length-1]) {
+      case '0':
+        max = Math.floor((min + max) / 2)
+        break
+      case '1':
+        min = Math.ceil((min + max) / 2)
+        break
+      default:
+        console.log("something went wrong")
+    }
+
+    return [min, max]
+  }
+  let row = getIndexFromBSP(rowCode, 0, 127)[0]
+  let col = getIndexFromBSP(colCode, 0, 7)[0]
+
+  seats [row] = seats[row] || []
+  seats [row] [col] = (row*8)+col
+}
+// i just scrolled thru and found the one empty seat
+console.log(seats.filter(row => row.length>7))